How to test and safely keep using your janky RAM without compromising stability using memtest86+ and the memmap kernel param.
Dealing with faulty RAM modules in 2026
https://blog.kumio.org/posts/2026/01/memtest86plus.html
https://blog.kumio.org/posts/2026/01/memtest86plus.html
How to test and safely keep using your janky RAM without compromising stability using memtest86+ and the memmap kernel param.
6 Comments
F04118F@feddit.nl · 4 pts · 222d
This is amazing!! I had no idea this was possible!
One point of feedback: not having worked with memmap before, it is not immediately obvious to me which hex means what (I am guessing RANGE@START? ). Would be nice to have a link to an explanation there.
I am definitely sharing this, thank you for writing the blog!
kumi@feddit.online · 6 pts · 222d
Thank you, I'm glad you like!
I just have the link to the kernel docs because I think they do a better job explaining it than I would 😁
But yeah, basically. Except for this use-case you want
RANGE$STARTnot@. And you can use human sizes like128M$RANGE.jwt@programming.dev · 1 pts · 222d
Ooh, that rasdaemon looks interesting. thank for sharing!
Corbin@programming.dev · 1 pts · 221d
Well done. I recently revived the BadRAM kernel patch in order to do something similar; memtest86+ supports that functionality too, using , , , .
kumi@feddit.online · 4 pts · 221d
I'm curious: What's motivating you to do that when the memmap param can do the same without patching?
Corbin@programming.dev · 1 pts · 203d
BadRAM specifiers can apply to stripes of memory corresponding to certain physical hardware failures. The memmap hack only allows for contiguous allocations. BadRAM's intended for repurposing consumer-grade RAM that might normally be thrown out, not for reconfiguring motherboards that have strange layouts.